Recently, advancements of electronics have resulted in markedly shortening of the access time to images so that rapid access for silver halide photographic materials is desired. Enhanced sensitivity of silver halide grains is also required and tabular silver halide grains are often employed. Tabular silver halide grains increase the grain projected area, leading to an increased light-receiving area per grain and tabular grains also increase adsorption of a sensitizing dye, leading to enhance spectral sensitivity.
U.S. Pat. Nos. 4,386,156, 4,399,215, 4,414,304 and 4,425,425 disclose tabular silver halide grains used in photographic materials.
To enhance rapid processability, there has been attempted reduction of the amount of gelatin used as a protective binder for silver halide grains to promote developing, fixing, washing and drying. However, reduction of gelatin deteriorated pressure resistance of silver halide grains. To overcome this problem, attempts to improve preparation of silver halide grains have been made, but silver halide grains with enhanced pressure resistance as well as high sensitivity and less fogging have not yet achieved.
A technique of incorporating latexes as a plasticizer to enhance pressure resistance was disclosed in JP-B 53-28086 (herein, the term, JP-B means a published Japanese Patent) and Research Disclosure, vol. 195, July 1980. A technique of employing latexes in combination with tabular silver halide grains was also disclosed in JP-A 2-135335 (herein, the term, JP-A means a unexamined and published Japanese Patent Application). In these techniques, however, reduction of gelatin to achieve rapid processing and the use of a large amount of a latex to enhance pressure resistance resulted in deterioration in physical property of layers, such as blocking (or sticking).
JP-A 4-214551, 4-340951, 5-53230 and 5-53237 disclose a technique of incorporating colloidal silica into a silver halide emulsion layer to enhance pressure resistance. According to this technique, deterioration in physical property was prevented, however, incorporation in effective amounts thereof produced disadvantages such that cracking occurred during storage of processed films. As a means for improving this, JP-A 6-95300 discloses a technique of surface-treating colloidal silica to introduce a functional group capable of crosslinking gelatin. Thereby, cracking during storage was prevented but reduction of sensitivity was marked, particularly when subjected to rapid processing. The use of natural or synthetic aqueous-soluble polymers is known to prevent reduction of sensitivity. However, incorporation of a large amount of the aqueous-soluble polymer produced problems such that the polymer leached out of a processed photographic material into a processing solution, resulting in stain in the solution or on rollers of an automatic processor. Accordingly, a silver halide photographic material with superior processability and a processing method thereof.